1. Field of the Invention
The present invention relates to a terminal connector having a cover for use in electrical connection, specifically in audio and video equipment.
2. Description of the Related Art
Referring to FIG. 7, a conventional terminal connector, shown generally at 100xe2x80x2, includes an electrically conductive terminal plate 14 mounted on an insulative circuit board 10. A terminal 15 is secured to insulative circuit board 10 by a screw portion 17 threaded through a screw hole 16 in terminal plate 14. A knob 19xe2x80x3, affixed projecting away from terminal 15 enables screwing and unscrewing of screw portion 17 for making electrical connection, as will be explained. Conventional terminal connectors 100xe2x80x2, are generally constructed in a four-gang (shown) or eight-gang (not shown) configurations.
Circuit board 10 includes four cylindrical portions 11. Cylindrical portions 11 are integrally formed on a first surface of circuit board 10 and surround part of terminals 15 near the first surface of insulative circuit board 10. Cylindrical portions 11 help avoid lead wire shorts and reduce the chance of electrical contact with a person or an object. Knob 19xe2x80x3 of terminal 15 also protrudes away from the first surface. Cylindrical portions 11 each have at least one lead wire insertion notch 12 in an outer periphery.
A through hole 13, formed in insulative circuit board 10, accommodates adjustable screw portion 17 of terminal 15. Screw portion 17 is centered in cylindrical portion 11. Around through hole 13, a plurality of insertion holes 20 permit insertion of one or more press-in lock pieces 21 and a terminal portion 22 of terminal plate 14 into selected insertion holes 20 to fix terminal plate 14 firmly to insulative circuit board 10.
A fit hole 25, shaped to receive plug connection portion 23, passes through the center of knob 19xe2x80x3. A plug insertion opening 26, having a diameter greater than that of fit hole 25, is formed at the top of knob 19xe2x80x3 for guiding as will be described.
A terminal body 59xe2x80x2, made from electrically conductive material, includes cylindrical plug connection portion 23, suitable for accepting insertion of a conventional banana tip, a wire end, or other conductor. Also included in terminal body 59xe2x80x2, a collar 18 is pulled down into stabilizing contact with insulative circuit board 10 when screw portion 17 is tightened. Terminal body 59xe2x80x2 accepts a press fitted knob 19xe2x80x3 to form terminal 15.
Terminal body 59xe2x80x2 is conventionally formed by cold forging or a similar process. Through cold forging, conventional cylindrical plug connection portion 23, collar 18, and screw portion 17 are simultaneously formed.
After integration of terminal plates 14 to insulative circuit board 10, terminals 15 are threaded into terminal plates 14 through screw holes 16. When each screw portion 17 is tightened, collar 18 of terminal 15 contacts terminal plate 14 and an end portion of screw portion 17 protrudes below a second surface of insulative circuit board 10. After tightening, an end portion of screw portion 17 is mechanically flattened to form a preventive bulged portion 31 and disrupt a continuous helical thread formed on screw portion 17. Preventive bulged portion 31 prevents terminal 15 from disengaging screw hole 16 or from being lost during later adjustment.
Once terminal plates 14 and terminals 15 are connected to circuit board 10, knobs 19xe2x80x3 are loosened sufficiently to allow insertion of at least one lead wire (not shown).through insertion notches 12. When screw portion 17 of terminal 15 is tightened toward screw hole 16 in terminal plate 14, a bottom surface of collar 18 and a top surface of terminal plate 14 sandwich the lead wire (not shown) for electrical contact. A banana plug (not shown), or other conductor, may be inserted into terminal 15, through plug insertion opening 26 and into plug connection portion 23, for electrical connection to the lead wire. More than one lead wire may be captured this way, and connected to a connector inserted into plug connection portion 23 or alternatively to terminal portion 22.
Referring additionally to FIG. 6, conventional terminal connectors 100xe2x80x2, positioned now in an eight-gang configuration, illustrate positioning of insertion notches 12 through an outer periphery of terminals 15. Here, knobs 19xe2x80x3 are labeled 19xe2x80x3a through 19xe2x80x3d, indicating each individual knobs 19xe2x80x3 within the configuration.
Referring additionally to FIG. 5, a non-conventional terminal connector 100, previously developed by the applicant, includes electrically conductive terminal plate 14 mounted to insulative circuit board 10xe2x80x2. Terminal 15 is secured to insulative circuit board 10xe2x80x2 by screw portion 17 threaded into screw hole 16 in terminal plate 14. A knob 19xe2x80x2, fixed projecting away from terminal 15 enables screwing and unscrewing of screw portion 17 for making electrical connection, as will be explained.
Cylindrical portion 11, surrounding a part of terminal 15 near the first surface of insulative circuit board 10xe2x80x2, helps avoid lead wire shorts and reduces the chance of electrical contact with a person or an object. Cylindrical portion 11 is formed cylindrically about a center axis and has at least one wire insertion notch 12 in its outer periphery. Cylindrical portion 11 includes at least one lock portion 38 protruding from an upper edge of cylindrical portion 11 and facing the central axis. Lock portions 38, combined with retention portions 39 (later described) act to prevent terminal 15 from separating from terminal plate 14. In this figure, insulative circuit board 10xe2x80x2 has four cylindrical portions 11 formed on the first surface.
Each terminal 15 comprises knob 19xe2x80x2 protruding away from the first surface and generally cylindrical in shape. Fit hole 25 contains plug connection portion 23, and passes through the center of knob 19xe2x80x2. Plug insertion opening 26 is formed at the top of fit hole 25. A circular recess at the bottom of fit hole 25 engages a collar 18. Knob 19xe2x80x2 is made from an electrically insulating material such as resin.
An electrically conductive terminal body 59 is an integrally formed element with plug connection portion 23 at a first end, and a minor diameter portion 42 at a second end. Terminal body 59 is integrally formed from with plug connection portion 23 suitable for accepting the insertion of a conventional banana tip, a wire end, or other conductor. Collar 18 is disposed at a first intermediate location and contacts plug connection portion 23. A screw portion 17 is disposed at a second intermediate location and contacts a minor diameter portion 42.
Plug connection portion 23, collar 18, screw portion 17, and minor diameter portion 42 all have circular shapes about a common axis. That is, plug connection portion 23 has a cylindrical shape, collar 18 has a disk-like shape, screw portion 17 has a cylindrical-column shape, and minor diameter portion 42 has a cylindrical-column shape. Screw portion 17 contains a continuous helical thread having a minor diameter measured from a central axis of screw portion 17. Minor diameter portion 42 has a diameter, measured from the same central axis, less than the minor diameter of screw portion 17. Minor diameter portion 42 serves as a guide as is later described.
Knob 19xe2x80x2 and terminal body 59 are fixed to each other by both the engagement of collar 18 and the swaging of a top rim of plug connection portion 23 to form a complete terminal 15. This engagement prevents terminal body 59 and knob 19xe2x80x2 from rotating with respect to each other and from losing contact with each other as terminal 15 adjusts.
Knob 19xe2x80x2, on terminal 15, has integral circular retention portions 39, formed around an exterior circumference and projecting away from the central axis. Knob 19xe2x80x2 has a diameter, relative to the central axis, smaller than that of lock portions 38 formed on cylindrical portion 11 so as to allow adjustment of terminal 15 within cylindrical portion 11.
The inner diameter of cylindrical portion 11, relative to the central axis of terminal 15, is greater than that of retention portions 39 to allow insertion of terminal 15 from the second surface of circuit board 10xe2x80x2. However, the inner diameter of lock portions 38 is smaller than the outer diameter of retention portions 39 so as to prevent free passage of terminal 15 away from the first surface of circuit board 10xe2x80x2 through cylindrical portion 11. Together, lock portions 38 and retention portions 39 retain terminal 15.
Formed on the second surface of circuit board 10xe2x80x2 are through holes 43. Through holes 43 have a diameter larger than the inner diameter of cylindrical portion 11, but smaller than the outer diameter of cylindrical portion 11. Through holes 43 pierce the first surface of insulative circuit board 10xe2x80x2 and accommodate terminal plate 14.
Also formed around through hole 43, on the second surface of circuit board 10xe2x80x2, is a plurality of integral insertion slots 40 with lock steps 41 for guiding and retaining terminal projections 22 of terminal plate 14. Lock steps 41 are formed about a central axis of through hole 43 perpendicular to terminal portions 22 of terminal plate 14.
Each terminal plate 14, consisting of an electrically conductive material, is formed as a disk portion having a central axis and contacts collar 18 of terminal 15 around cylindrical threaded screw hole 16. Screw hole 16 enables threaded electrical contact between terminal 15 with screw portion 17 and terminal plate 14.
In each terminal connector 100, since minor diameter portion 42 has a diameter smaller than that of screw hole 16, minor diameter portion 42 functions to align and guide terminal plate 14 during assembly. After assembly of terminal connector 100, banana clips, wire leads or other contacts may be inserted in plug insertion opening 26 of terminal 15 or through insertion notches 12 of cylindrical portion 11, to enable electrical contact to terminal projections 22 of terminal plate 14.
Now collectively referring to FIGS. 5 through 7, when such eight or four-gang terminal connectors 100, 100xe2x80x2 are used, individual knobs 19xe2x80x2, 19xe2x80x3 may be selectively colored to indicate specific signal use. For example, in FIG. 6 knobs 19xe2x80x3a, 19xe2x80x3b may be formed in a red color to indicate a positive signal use, and knobs 19xe2x80x3c, 19xe2x80x3d may be colored black to indicate a negative signal use.
The multiple terminal connectors 100, 100xe2x80x2 with pre-labeled knobs 19xe2x80x2, 19xe2x80x3 present several problems concerning manufacturing, assembly, and later use.
First, during assembly, knobs 19xe2x80x2, 19xe2x80x3 are molded in advance in specific colors according to a predicted use. Once molded, knobs 19xe2x80x2, 19xe2x80x3 are installed into circuit board 10, 10xe2x80x2, again according to their predicted use. Thus during assembly, pre-labeled knobs 19xe2x80x2, 19xe2x80x3 must be pre-positioned thus prohibiting adaptation to real-time customer demand.
Second, during assembly, pre-positioning knobs 19xe2x80x2, 19xe2x80x3 complicates assembly steps and requires additional manufacturing storage.
Third, manufacture of pre-colored knobs 19xe2x80x2, 19xe2x80x3 requires a raw material batch separate from the patch used to form insulative circuit boards 10, 10xe2x80x2. This complicates the manufacturing process and increases manufacturing or supplier costs.
Fourth, during assembly of terminal connectors 100, 100xe2x80x2 terminals 15 are not replaceable where assembled incorrectly. In FIGS. 6 and 7, bulged portion 31 prevent non-destructive disassembly of terminal 15 from circuit board 10. In FIG. 5, retention portion 39 and lock portion 38 combined with snap-in terminal plate 14 prevent non-destructive disassembly of terminal 15 from circuit board 10xe2x80x2. Thus, preventing salvage of improperly assembled terminal connector 100, 100xe2x80x2. As a result, even a single improperly assembled terminal connector 100, 100xe2x80x2 will render a complete four or eight-gang terminal connector defective thereby increasing manufacturing losses and costs.
It is an object of the present invention to provide a terminal connector allowing color labeling during final assembly.
It is a further object of the present invention to provide a terminal connector whose knob is designed to receive a replaceable snap-on cover.
It is a further object of the present invention to provide a terminal connector whose knob is designed to receive a replaceable snap-on cover containing an insertion preventive lid.
It is a further object of the present invention to provide a terminal connector allowing easy storage, assembly, adjustment, and readjustment that minimizes manufacturing defect rates.
It is a further object of the present invention to provide a terminal connector allowing replaceable non-destructive re-labeling by shape or color.
The present invention relates to a terminal connector including a knob at its outer end. A knob cover snaps into the knob to enable rotation of the knob. The knob cover has resiliently urged lock tabs which snap over lock steps on the knob and into grooves beyond the lock steps. The sides of the lock tabs engage sides of the grooves to transmit torque to the knob. The knob covers are color coded so that selected colors can be installed on a selected knob to indicate its function. An insertion prevention lid is integrally molded over a plug insertion opening of the knob cover to prevent insertion of a connector plug therein. A frangible perimeter of the insertion prevention lid permits its removal to enable insertion of a connector plug.
According to an embodiment of the present invention there is provided a terminal connector comprising: a terminal including a terminal body, a means on a first end of the terminal body for attachment to an external element, a knob on a second end of the terminal body, at least one lock step on an exterior surface of the knob, at least one groove adjacent the lock step in an exterior surface of the knob, a knob cover, the knob cover fitting onto the second end over a portion of the knob, a lock tab resiliently attached to the knob cover, the lock tab resiliently engaging the lock step when the knob cover is pushed onto the knob, and sides of the lock tab engaging sides of the groove to resist relative rotation.
According to another embodiment of the present invention there is provided a terminal according wherein: the lock step on the knob extends radially on the exterior surface of the knob, the groove extends from a bottom edge of the lock step, the groove having a first and a second side perpendicular to the bottom edge of the lock step and generally axial to the knob, and the first and second side transmitting torque from the knob cover to the knob.
According to another embodiment of the present invention there is provided a terminal connector wherein: the knob cover has a generally cylindrical shape surrounding an axial cavity formed concentric to the knob, the lock tab formed in an interior surface of axial cavity, the lock tab having a top surface and a third and a fourth side orthogonal to the top surface, the top surface engaging the lock step to retain the knob cover on the knob, and the third and fourth side disposed parallel to and engaging the first and second side of the groove thereby transmitting torque from the knob cover to the knob.
According to another embodiment of the present invention there is provided a terminal connector wherein the knob cover further comprises: a top portion formed on a top end of the knob cover, a plug insertion opening centered in the top portion axial to the knob, and the plug insertion opening having an inner diameter and permitting plug access into the knob.
According to another embodiment of the present invention there is provided a terminal connector wherein the knob cover further comprising: an insertion prevention lid molded across the plug insertion opening, the insertion prevention lid including a frangible portion connecting the insertion preventive lid to the knob cover, the insertion prevention lid being smaller than an inner dimension of the knob, and the frangible portion permitting easy breakage thereof for removing the insertion prevention lid thereby permitting plug access to the plug insertion opening.
According to another embodiment of the present invention there is provided a terminal connector wherein: the insertion preventive lid and the frangible portion have at least one integral cross groove extending from a central axis to the inner diameter portion of the plug insertion opening, and the cross groove concentrates breaking stress for the frangible portion thereby facilitating the plug access to the plug insertion opening.
According to another embodiment of the present invention there is provided a knob cover comprising: an axial cavity fittable over a knob, a plug insertion opening at an end of the axial cavity, an insertion prevention lid integrally molded across the plug insertion opening, the insertion prevention lid preventing access of a plug to the plug insertion opening, a frangible portion at a perimeter of the insertion prevention lid, and the frangible portion permitting easy breakage thereof for removing the plug insertion prevention lid thereby permitting plug access to the plug insertion opening.
According to another embodiment of the present invention there is provided a terminal connector comprising: an insulative circuit board, a plurality of terminals rotatably fixed to a first surface of the insulative circuit board, the terminals each having a knob fixed into a top portion of the terminal, a knob cover replaceably fixed onto a top portion of at least one knob, the knob cover permitting manual rotation of the knob on the terminals for attachment to the circuit board, and the knob cover including a selectable color for identifying a function of its terminal.
According to another embodiment of the present invention there is provided a terminal connector wherein: each of the knobs on the insulative circuit board have an identical color.
According to another embodiment of the present invention there is provided a terminal connector further comprising: a plurality of lock steps radially disposed on the knobs, a plurality of lock tabs on an interior diameter of the knob cover, and the knob cover fixed onto the knob by elastically engaging each of the lock tabs to each of the lock steps thereby replaceably retaining the knob cover on the knob.
According to another embodiment of the present invention there is provided a terminal connector comprising: an insulative circuit board, a plurality of terminal plates affixed to a second side of the insulative circuit board, each the terminal plate having a screw hole, a plurality of terminals each having threaded portions threadably engaged to each terminal plate, means for preventing the terminals from losing threaded engagement to the terminal plates, a knob covering a first portion of each terminal to enable manual rotation of each terminal, a knob cover fitted and fixed to each knob, and each knob cover including a selectable color for identifying a function of its terminal.
According to another embodiment of the present invention there is provided a terminal connector wherein: a top portion of each knob cover has an integrally formed plug insertion opening coaxial to each knob, the plug insertion openings having an inner diameter, and an improper insertion preventive lid detachably attached to an inner diameter thereby covering the plug insertion openings.
According to another embodiment of the present invention there is provided a terminal connector wherein: a top portion of each knob cover has an integrally formed plug insertion opening coaxial to each knob, the plug insertion opening having an inner diameter, and improper insertion preventive lid detachably attached to an inner diameter thereby covering the plug insertion opening.
The above, and other objects, features and advantages of the present invention will become apparent from the following description read in conjunction with the accompanying drawings, in which like reference numerals designate the same elements.